Vibrating roll and method



July 9-, 1963 J. B. JONES 3,09

VIB ETHOD Original Filed July 28, 1 960 v 3 Sheets-Sheet 1 Fig, I m

IN VEN TOR. JAMES BYRON JONES ATTORNEY July 9, 1963 J. B. JONES3,096,672

VIBRATING ROLL AND METHOD Original Filed July 28, 1960 3 Sheets-Sheet 2July 9, 1963 J. B. JONES 3,096,672

VIBRATING ROLL AND METHOD Original Filed July 28, 1960 s Sheets-Sheet sIN V EN TOR. JAMES BYRON JONES MAM ATTORNEY United States Patent3,096,672 VIBRATING ROLL AND METHOD James Byron Jones, West Chester,Pa., assignor to Aeroprojects Incorporated, West Chester, Pin, acorporation of Pennsylvania Continuation of application Ser. No. 45,926,July 28, 1960. This application Jan. 9, 1962, Ser. No. 169,700

17 Claims. (CI. 80-60) This invention relates to a rolling mill, andmore particularly to a rolling mill for reducing the cross-section ofmetals in which vibratory energy is delivered to the surfaces of themetal being rolled.

This application is a continuation of my co-pending application SerialNo. 45,926 filed on July 28, 1960, now abandoned, and entitled RollingMill.

Rolling is a very common and useful metal working process and includesboth the rolling of flat strip or sheet and of round rod, smoothcylindrical rolls generally being used for rolling sheet and groovedrolls for rolling rod. As a rule, at least two rolls are used whichrotate in opposite directions at the same peripheral speed, the distancebetween such rolls being slightly less than the height of the material,so that the rolls grip the metal, drawing it in, reducing the section,and increasing its length in proportion to such reduction. Sometimestension reels are used to pull the strip through the work rolls. Often atwoaroll or two-high rolling mill is inadequate for a given rollingsituation, and various roll combinations are used, such as three-high,four-high, ninehigh, etc; also cluster mills may be used. The additionalrolls act as stifleners and supporters for the rolls in contact with thework, the working rolls usually being smaller than the backing rolls inview of the known roll-diameter to stock-thickness ratio which permitsrolling to thinner sized with smaller rolls than with larger rolls.

Moreover, in roll-forming thin sheet, very high roll pressures arenecessary to force the metal to flow, and surface friction becomes veryimportant, so that the high pressures are practicable only by the use ofsmall-diameter working rolls where the area of contact between roll andsheet is small. In the variation of rolling known as crossrolling,sometimes used in the making of seamless tubing and the straightening ofrounds, the rolls are rotated in the same direction with the metal beingrotated as it passes between the rolls. Another variation is packrolling, in which sheets are sandwiched in layers and the entiresandwich is rolled.

Rolling, be it hot-rolling (wherein the metal billet is heated prior torolling) or cold-rolling, involves the working of the metal beingrolled. Notwithstanding the working achieved by rolling, many metalspossess large grain sizes even after rolling, although a smaller grainsize would be preferred for various reasons. In particular, reducedgrain size of beryllium is desirable, since the cast metal exhibitsanisotropic large-size crystals which fracture readily on the basalplane under tensile stress, resulting in poor room-temperatureductility, machining difliculties such as chipping and cracking, etc.The use of vibratory energy to reduce grain size of metals has beensuggested previously, but such application has involved the treatment ofmolten, rather than solid, metal or the use of a fluid coupling mediumto deliver the energy from the source of vibration to the solid metalbeing treated. Moreover, the type of vibration used has been of thehammering type; i.e., vibration essentially perpendicular to the surfacebeing treated.

In connection with the present invention, it has been found that reducedgrain size of metals may be obtained without the necessity for vibratingthe metal while the metal is in a molten or mushy state and without the3,096,672 Patented July 9, 1963 use of a fluid coupling medium (thelatter being possible notwithstanding the gap or discontinuitynecessarily presout between vibration source and solid metal to betreated, such gaps or discontinuities even though seemingly slight beingknown to the art to ordinarily occasion energy losses, formation ofstanding waves, etc.), provided the type of vibration describedhereinbelow is utilized and provided sufficient force is applied to themetal and provided the energy level of the vibration delievered to themetal is adequate. It is to be noted that force is generally notutilized in connection with vibratory energy applied to or thoughfluids, and that the energy level of the vibratory energy applied to orthrough fluids is generally considerably less than the energy levelsuitable for use in relation to the present invention.

Furthermore, it has been found that, not only can grain size be reducedby means of rolling in accordance with the present invention, but alsothe static working forces requisite for rolling can be reduced by meansof the present invention compared with the forces required in aconventional rolling mill. In certain situations, it is more importantto reduce the static working forces requisite for rolling than toachieve a reduction in grain size. It appears that, whereas metalcrystals usually undergo workhardening during plastic deformation, thistype of vibratory energy can induce a plasticity or softening effect insolid metals, an effect which is not associated with temperature andwhich acts to alter metal properties transiently and yet sufficiently sothat lesser rolling and/or tensioning forces are required to produce thedesired end result. However, the aforesaid conditions apply inconnection with the present invention, namely, the conditions as to typeof vibration, force level, and energy level of vibration.

This invention has as an object the provision of a novel rolling mill.

This invention has as another object the provision of a rolling processin which reduced rolling forces may be utilized to achieve the rollingof metals.

This invention has as yet another object the provision of a rollingprocess which will enable small grain size metals to be achieved.

This invention has as a further object the provision of a rollingprocess in which improved properties and characteristics are imparted tothe metals being rolled.

Other objects will appear hereinafter.

For the purpose of illustrating the invention there is shown in thedrawings a form which is presently pre-- ferred; it being understood,however, that this invention is not limited to the precise arrangementsand instrumentalities shown.

Referring to the drawings wherein like reference characters refer tolike parts:

FIGURE 1 is a front elevational view of an embodiment of the ultrasonicrolling mill of the present invention, with parts being shown in sectionand broken away for the sake of clarity.

FIGURE 2 is a vertical section taken on line 22 of FIGURE 1.

FIGURE 3 is a photomicrograph of 0.020 inch thick QMV cross-rolledberyllium revealing the relatively large grain size of beryllium whichhas been subjected to conventional rolling.

FIGURE 4 is a photomicrograph of 0.020 inch thick QMV beryllium whichhas been exposed to high-intensity shear-type vibration while thematerial was being reduced in thickness, and reveals the reduction ingrain size of such beryllium.

FIGURE 5 is a sectional view through the vibratory device and supportfor one end of a working roll of the rolling mill of the presentinvention.

FIGURE 6 is an enlarged cross-sectional view through an axial planewithin the encircled portion in FIGURE 1.

Thus, rolling according to the present invention comprises the formationof metallic materials of desired thickness and/ or shape by translatingthe metal billet or partially-formed elongated metal between vibratingwork rolls which apply vibration to the surfaces of the metal or metalscontacting said rolls in the region so contacted, said vibration beingessentially parallel to (in the plane of) said contacted surfaces (i.e.,vibration essentially perpendicular to the static force which is alsoapplied through said rolls). The invention contemplates applying suchvibration to the top surface and to the bottom surface of the billet ifa single sheet is being rolled, and to the top surface of the top billetand to the bottom surface of the bottom billet if two or more layers ofstock are being rolled simultaneously.

Inasmuch as vibratory tools, and in particular ultrasonic tools, areresonant vibrating systems, i.e., systems for which, because theefliciency of conversion of the driving energy (usually electricalenergy) into acoustical or vibratory energy is highest at the resonantfrequency, design of the vibrating parts of these tools is in accordancewith well known equations which relate resonant frequency to physicalproperties and especially to the physical dimensions of the materials ofconstruction, the frequency of vibration employed in connection with thepresent invention is primarily related to the size of the vibratingparts of the apparatus and the materials of which these vibrating partsare made. Thus, large tools usually have a comparatively low resonantfrequency (60 cycles per second or even much less) and small toolsusually have a comparatively high resonant frequency kilocycles persecond and even much more), with a tool having a resonant frequencybetween these extremes being generally of intermediate size.

It is to be noted that, for the purposes of this invention, ultrasonicvibration is defined as high-intensity and/ or high-frequency vibration,it being known to the art that the distinction between audible andinaudible frequencies per se is arbitrary.

Because the maximum permissible power input to these devices is alsorelated to their physical dimensions, large low-frequency tools aregenerally able to handle more power than small high-frequency tools,other things being equal. It will be appreciated, therefore, thatapparatus according to the present invention whose vibrating parts areof the comparatively-large, comparatively-low resonant-frequency, andcomparatively-high-power-input type may have more utility with larger ormultiple billet rolling than may apparatus of the intermediate andsmaller types. However, economical use of the intermediate and smallertypes of apparatus, in preference to the large type, may be possible, inconnection, for example, with the rolling of fine ribbon or wire fromcomparatively small billets.

It is clear, therefore, that the frequency of vibration of the vibratingparts of the apparatus of this invention is not related to the physicalproperties of the metal billet, viz., to any resonant properties thebillets may have, and especially is this so since, under the influenceof the rolling deformation, any such resonant properties may be expectedto change as the dimensions of the material being rolled change duringthe rolling process. Power-handling capacity of the vibrating parts ofthe apparatus, rather than frequency of vibration, is an importantfactor in its construction and operation, since in any case sufficientvibratory energy of the appropriate type must be delivered to thesurface or surfaces of the metal being rolled to obtain the transienteffects hereinabove noted.

The applied static force, of course, must be sufficient to takeadvantage of the briefly altered properties of the metal occasioned bythe vibration, which vibration as has been indicated is not primarily ofthe hammering type but is largely parallel to the plane of thevibratorilycontacted surfaces of the metal being rolled, and causereduction of the metals cross-section.

Altered properties, as used herein, does not imply any melting of themetal being rolled, since the subject invention does not involvebringing of the metal to its melting point temperature; it indicatesthat the metal is distortable under the influence of the vibration butis less easily distorted when the vibration is discontinued, which is aphenomenon observed when the type of vibration mentioned above isemployed during the rolling process. The introduction of the vibratoryenergy will induce some temperature rise in addition to the riseassociated with reducing the cross-section, but melting of the metal isunnecessary and, in fact, undesirable in connection with the subjectinvention and has not been known to occur (as determined by the use ofthermocouples or approximated from a metallographic examination of across-section of the rolled product in the ordinary magnification rangeup to about 500 diameters) even under excessively high powers, for undersuch conditions the metal tends to be destroyed by the vibration ratherthan melted by it.

Hot-rolling, i.e., initiation and/or conducting of the rolling processat elevated temperatures below the fusion temperature (melting point orsolidus temperature) of any of the pieces being rolled is within thescope of the present invention. A wide variety of metals may be rolledin accordance with this invention, and, while the rolling of most metalscan be effected in the ambient atmosphere, such rolling may also beaccomplished under vacuum conditions or in inert gaseous atmospheres.

It will be appreciated that, since metals are known to differ as totheir properties and alloys of metals are also known to possessdifferent properties, their reaction to the type of vibration employedherein may also be expected to differ so that @ditfering amounts offorce and vibratory energy level may be necessary in each case. However,the testing and adjustment of these rolling conditions are well withinthe skill of one skilled in the art.

The rolling mill 6 of the present invention comprises a pair of uprightrolling mill frame members 8 and 10 spaced apart, between which theworking rolls 12 and 14 are carried. The working roll 12 may be adjustedvertically in respect to the working roll 14 which is spacedtherebeneath, and which is fixedly positioned.

The working roll 12 is engaged with the backup discs 16 of the backingroll 18 and the backup discs 20 of the backing roll 22. The backingrolls 18 and 22 are identical, and accordingly the description set forthbelow will be confined to the backing roll 18.

The backup discs 16 of backing roll 18 are engaged in mating grooves 24of pressure roll 26. Similarly, the backup discs 20 of backing roll 22are matingly engaged in the grooves 28 of pressure roll 39.

The working roll 14 is engaged by the backup discs 32 of backing roll'34, and the backup discs 36 of the backing roll 38. The backup discs 32of backing roll 34 are received within the grooves 40 of pressure roll42, and the backup discs 36 of backing roll 33 are received within thegrooves 44 of pressure roll 46.

The bearings for the working roll 12, the backing rolls 18 and 22, andthe pressure rolls 26 and 30 are such as to permit such rolls to beadjusted in respect to the frames 8 and 10 so as to accommodate fordifferent gap distances between the working rolls 12 and 14. Thebearings for the aforesaid rolls permit rotation of the rollsnotwithstanding the application of very high pressures. The working roll14, the backing rolls 34 and 33, and the pressure rolls 42 and 46 arefixedly positioned in respect to the frame members 8 and 10, so thatwhile such rolls may be rotated under high pressure, they are notadjustable vertically, since the same is unnecessary due to theadjustability of the working roll 12, the backing rolls 18 and 22, andthe pressure rolls 26 and 30 as aforesaid.

The metal sheet or strip to be rolled is introduced, as for examplebetween front and back power reels intermediate the working rolls .12and 14. Phe working r'olls 12 land 14 are, except for their bearings,substantially identical. Thus, the working roll 12 comprises a centralcylindrical portion 48 of maximum diameter, which is spaced from asimilar central cylindrical portion 50 of maximum diameter of workingroll '14. A pair of exponential 'horns 52 and 54 are disposed on eitherside of the central cylindrical portion 48 of working roll 12, withtheir portions of maximum diameter being contiguous to the juxtaposedend of the central cylindrical portion 48. Similarly, exponential horns56 and 58 are secured to the central cylindrical portion 50 of workingroll 14, with the maximum diameter portions of each such [horn joiningthe juxtaposed end face of the central cylindrical portion 50.

Referring to FIGURE 5, a cylindrical coupler 60 is integral with ormetallurgically attached to the minimum diameter end of the exponentialborn 54. A magnetostrictive transducer 62 is metallurgioally bonded inendto-end contact with the other end of the cylindrical coupler 60. Themagnetostrictive transducer 62 is of con ventional construction andcomprises :a laminated core of nickel, nickel-iron lalloy, Permendur (aniron-cobalt alloy), Alfenol (an aluminum-ironaalloy), or othermagnetostrictive material, properly dimensioned [to insure resonancewith the frequency of the alternating current applied thereto so as tocause it to change in length according to its coelficient ofmagnet-ostriction. The detailed construction of a simplemagnetostrictive transducer which, in the illustrated embodiment,comprises a nickel stack, is well known to those skilled in this art anddoes not form apart of the present invention, and accordingly nodetailed description of its construction will be made herein.

The magnetostrictive transducer 62 includes the polaru'zing coil 64 andthe excitation coil 66. The desirability of magnetically polarizing themagnetostrictive transducer 6'2 by means of polarizing coil 64 in orderfor the metal laminations in the magnetostrictive transducer 62 toefiiciently convert the applied R.F. energy from excitation coil 66 intoelastic vibratory energy will be readily understood by one skilled inthe art.

It will be appreciated by those skilled in the art that in place of themagnetostrictive transducer 62 shown in [the drawings, other known typesof transducers may be substituted. For example, electrostrictive orpiezoelectric transducers, made of barium titanate, quartz crystals,lead tit-anate, lead zirconate, etc, may be utilized. Magnetostrictivetransducers conventionally operate in the frequency range from about8,000 cycles per second to about 60,000 cycle per second, whileelectrostrictive or piezoelectric transducers have 'a frequency rangeextending to about 150,000 cycles per second. Various other types of'devices may be used to excite the appropriate components of the subjectinvention, such as mechanical vibratory devices, electromagneticdevices, hydraulic devices which convent fluid pressure to mechanicalvibration, etc.

The cylindrical coupler 60 is supported by a support mount 68. Thesupport mount is a force-insensitive mount, namely a mount which enablesvibratory energy to be applied to a work area with force and under aload without an appreciable shift in frequency of the device resultingfrom the load, and is described in U.S. Patents 2,891,180; 2,891,179;and 2,891,178. The disclosures of such patents are incorporated hereinby reference. The support mount 68 in the illustrated embodimentcomprises a cylindrical metal shell, such as a cylindrical steel shellor a shell of other suitable resonant material. Such shell 68 has alength equal to a single one-half wavelength. The shell 68 surrounds thecylindrical coupler 60, being concentric therewith and spaced therefrom.At the end of the shell 68 which is furthest from the magnetostrictivetransducer 62 there is a radially inwardly disposed flange '70 which ismetallurgically bonded to the cylindrical coupler 60. The end "72 ot thesupport mount "the slip rings 98, 100, 102, and 104 respectively.

68 opposite from the flange 70 is free from any attachment, andaccordingly when the vibratory device is vibrating a true node developin the support mount 68 at flange 74, which is one-quarter wavelengthdistant (from the free end 72 cf the support mount 68.

The cylindrical coupler 60 and the Elmore support mount 68 extendthrough an opening 76 in the rolling mill frame member 10. The flange 74of the support mount 68 is supported by a cylindrical sleeve 78 which isconcentric to and spaced from the support mount 68. The sleeve 78 isrotatably supported by a ballbearing 80 in a bracket 82. The bracket 82is secured to the outer side of the rolling mill frame member 10 bybolts 84. Thus, one end of the working roll 12 is rotatably supported onthe frame member 10.

A gear 86 is secured around the end of the sleeve 78 away from the framemember 10. A driver gear 881 meshs with the gear 86. The drive gear 88is mounted on a drive shaft 90 which is connected to a source of powerfor rotating the working roll 12.

A cylindrical housing 92 (preferably of nonmetallic material, such asplastic) is secured to the gear 86, and extends around themagnetostrictive transducer 62. A cylindrical hub 94 of an electricalinsulating material is secured to the end of the housing 92 by anannular flange 96. Four annular slip rings 98, 100, 102, and 104 of anelectrically conductive metal are secured around the hub 94 inlongitudinally spaced relation. Wires 106 and 108 electrically connectthe ends of the polarizing coil 64- of the magnetostrictive transducer62 to the slip rings 98 and respectively. Wires 110 and 112 electricallyconnect the ends of the excitation coil 66 to the slip rings 102 and 104respectively. The wires 106, 108, 110, and 11-2 extend longitudinallythrough the housing 92 and the hub 94, and then through radial holes inthe hub 94 to their respective slip rings.

A brush holder 114 of an electrically insulating material is providedadjacent the outer surface of the hub 94, and is supported from theframe member 10. The brush holder 114 carries four brushes 116, 118,120, and 122 which are insulated from each other, and slidably engage Aseparate spring 124 holds each of the brushes against its respectiveslip ring. Wires 126, 128, 130, and 132 extend through the brush holder114 and are electrically connected to the brushes 116, 118, 120, and 122respectively. The wires 126, 128, 130, and 132 are electricallyconnected to the power supply for the magnetostrictive transducer 62.

In the illustrated embodiment, the magnetostrictive transducer 62, thecylindrical coupler 60, and the exponential horn 54 are designed to beresonant at the applied operating frequency so as to deliver the optimumamount of power, and to have the joints, such as the joints between themagnetostrictive transducer 62 and the cylindrical coupler 60 andbetween the cylindrical coupler 60 and the exponential horn 54 andbetween the flange '70 and the cylindrical coupler 60 positioned at aloop of the Wave motion whereby the joints will not be appreciablystressed.

The exponential horns 52, 56, and 58 are each also provided with acylindrical coupler and a magnetostrictive transducer similar to thecylindrical coupler 60 and the magnetostrictive transducer 62 on theexponential born 54. The exponential horns 52 and 56 are rotatablysupported in bearing brackets 134 and 136 respectively mounted on therolling mill frame member 8. The exponential horn 58 is rotatablysupported in a bearing bracket 138 mounted on the rolling mill framemember 10. Each of the exponential horns 52, 56, and 58 is supported inits respective bearing block by an Elmore support mount, similar to thesupport mount 68, and a sleeve, similar to the sleeve 78.

The supporting sleeve for the exponential horn 5(, like the supportingsleeve 78 for the exponential horn 54, has

a gear 140 secured thereto. A driver gear 142 meshes with the gear 140.Driver gear 142 is mounted on a drive shaft 144 which is connected to asource of power for rotating the working roll 14. A cylindrical housing146 similar to the housing 92, is secured to the gear 140 and extendsover the magnetostrictive transducer of the exponential horn 56. Similarcylindrical housings 148 and 150 are secured to the mounting sleeves forthe exponential horns 52 and 58 respectively, and extend across themagnetostrictive transducers for the exponential horns 2 and 58. Each ofthe housings 146, 148, and 150 has a hub, similar to the hub 94, whichhas slip rings through which the polarizing coil and excitation coil ofeach of the magnetostrictive transducers are electrically connected tothe power source. A tube 152 extends longitudinally through the hub 94of the housing 92 into the housing 92. Similar tubes 152 extendlongitudinally through the hub of each of the housings 146, 148, and150. The tubes 152 are all connected to a source of air under pressure.The tubes 152 convey the air into the housings 92, 146, 148 and 150, andaround the magnetostrictive transducers therein to cool themagnetostrictive transducers. It will be clear that this is only onemethod of cooling and that other cooling means may be incorporated, suchas liquid cooling.

In order to permit the relatively free vibratory excursioning of thesurface of the cylindrical portions 48 and 50, the discs 16 and 32 areresonant members designed as fiexural discs with nodal support flanges16a and 32a. The flanges 16a and 32a flex under the influence ofvibration without interfening with the ability of the discs to transmitstrong forces on the surface of the cylindrical portions 48 and 50.

Rolls 18 and 34 support the resonant discs 16 and 32 only at their nodalflanges. The faces of the discs 16 and 32 do not contact the surfaces ofthe grooves 24 and 40. Forces applied as shown at F in FIGURE 6 aretransmitted from roll 26 to the flanges 16a and 32a. In turn, the discs16 and 32 will transmit the forces from their outer peripheral surfacesto the cylindrical portions 48 and 50.

In the operation of the rolling mill 6 of the present invention, theworking rolls 12 and 14 are rotated through the drive shafts 90 and 144and the driver gears 88 and 142. The Working rolls 12 and 14 may berotated in opposite directions or in the same direction according to thetype of rolling to be accomplished. The power source for themagnetostrictive transducers secured to the exponential horns 52, 5'4,56, and 58 is turned on to vibrate the working rolls 12 and 14longitudinally of the axis of rotation of the working rolls. For thispurpose, the magnetostrictive transducer secured to the exponential horn52 of the working roll 12 is vibrated 180 degrees out of phase with themagnetostrictive transducer secured to the exponential horn 54 of theworking roll 12. Thus, the magnetostrictive transducers secured to theexponential horns 52 and 54 are operating like a twoman saw to vibratethe working roll 12 longitudinally of its axis of rotation. Likewise,the magnetostrictive transducer secured to the exponential born 56 ofthe working roll 14 is vibrated 180 degrees but of phase with themagnetostrictive transducer secured to the exponential born 58 of theworking roll 12. However, the magnetostrictive transducer secured to theexponential horn 52 of the working roll 12 is vibrated 180 degrees outof phase with the magnetostrictive transducer secured to the exponentialhorn 56 of the working roll 14. Thus, the working rolls 12 and 14 arevibrated in opposite directions with respect to each other so that whenthe working roll 12 is vibratorily moving (excursioning) in onedirection, the working roll 14 is vibratorily moving (excursioning) inthe opposite direction. The magnetostrictive transducers may beconstructed to vibrate and may be vibrated at frequencies lower than theso-called ultrasonic frequencies, although the ultrasonic frequencies ofabove about 15,000 cycles per second are preferred.

With the working rolls 12 and 14 rotating and vibrating longitudinallyof their axis of rotation, the metal to be rolled is passed between theworking rolls 12 and 14. By properly spacing the working rolls 12 and14, they will apply sufiicient force to the metal to reduce thethickness of the metal and proportionately increase the surface area ofthe metal. At the same time the vibrating working rolls 12 and 14introduce primarily sheartype vibration into the surfaces of the metalpassing between the working rolls 12 and 14; it will be understood that,due to Poissons ratio, these rolls also introduce a component normal tothe surfaces of the metal.

High-intensity shear-type elastic vibration applied to the surfaces ofmetals, such as beryllium, as the metal passes between the working rolls.12 and 14 results in a substantial reduction in grain size of themetal. For example, FIGURE 3 is a photomicrograph of a 0.020- inch thickQMV beryllium which has been subjected to conventional rolling. FIGURE 4is a photomicrograph of a 0.020-inch thick QMV beryllium which has beenexposed to high-intensity shear-type ultrasonic vibration while thematerial was being reduced in thickness. As can be seen by a comparisonof FIGURES 3 and 4, the beryllium which has been ultrasonically treatedhas a reduced grain size as compared with the grain size of theberyllium which has been subjected to conventional rolling. It was foundthat, not only was grain size reduced but also that a reduction in therolling and tensioning forces associated with rolling the metal wasobtained as compared with the forces required in a conventional rollingmill.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential attributes thereof and,accordingly, reference should be made to the appended claims, ratherthan to the foregoing specification as indicating the scope of theinvention.

I claim:

1. A rolling mill for reducing the cross-section of a metal membercomprising a pair of rolls supported in spaced relation for rotationabout their longitudinal axes, means for maintaining the space betweensaid rolls less than the thickness of a metal member, means for rotatingsaid rolls about their longitudinal axes, said rolls being adapted toreceive therebetween and reduce the thickness of the metal member, andvibratory energy generating means being coupled to at least one of saidrolls so as to vibrate said one roll in a direction parallel to its axisof rotation.

2. A rolling mill in accordance with claim 1 in which said one roll issupported by a force insensitive mount.

3. A rolling mill in accordance with claim 1 in which the means forgenerating vibratory energy (generates vibratory energy within thefrequency range of 20 cycles per second to 250,000 cycles per second.

4. A rolling mill for reducing the cross-section of a metal membercomprising a pair of rolls supported in spaced relation for rotationabout their longitudinal axes, means :for maintaining the space betweensaid rolls less than the thickness of the metal member, means forrotating said rolls about their longitudinal axes, said rolls beingadapted to receive therebetween and reduce the thickness of the metalmember, and means for generating vibratory energy of a predeterminedfrequency and energy level so as to reduce the grain size of the metalin said metal member as the thickness of said metal member is beingreduced by translation between said rolls, said generating vibratoryenergy means being coupled to one end of each of said rolls so as tovibrate each of said rolls in a direction parallel to their axes ofrotation.

5. A rolling mill in accordance with claim 4 in which the means forvibrating the rolls vibrates one of the rolls 9 in the opposite[direction to the direction of vibration of the other roll.

6. A rolling mill in accordance with claim in which the means forgenerating vibratory energy for each of the rolls comprises separatemeans which are 180 degrees out of phase with each other.

7. A tolling mill for reducing the cross-section of a metal membercomprising a pair of rolls supported in spaced relation for rotationabout their longitudinal axes, means tor maintaining the space betweensaid rolls less than the thickness of a metal member, means for rotatingsaid rolls about their longitudinal axes, said rolls being adapted toreceive therebetween and reduce the thickness of the metal member, aresonant back up disc engaged with at least one of said rolls, apressure roll engaging said disc, and means (for generating vibratoryenergy of a predetermined frequency and energy level so as to reduce thegrain size of the metal in said metal member as the thickness of saidmetal member is being reduced by translation between said rolls, saidmeans for generating vibratory energy being coupled to at least one Otfsaid rolls so as to vibrate said one roll in a direction parallel to itsaxis of notation.

8. A rolling mill in accordance with claim 7 wherein said pressure rollengages said resonant disc only at a nodal flange on said disc.

9. A method of rolling a metal comprising passing a metal member betweena pair of rotating rolls, reducing the thickness of the metal member byapplying sufficient force through said rolls while said rolls areengaged with said metal member, and simultaneously vibrating at leastone of said rolls in a direction parallel to the surface of the metalmember being contacted as the thickness of said metal member is beingreduced by being passed between said rolls.

10. A method of rolling a metal comprising passing a metal memberbetween a pair of rotating rolls, reducing the thickness of the metalmember by applying sufiicient force through said rolls while said rollsare engaged with the metal member, and simultaneously vibrating each ofsaid rolls in a direction parallel to the surface of the metal memberbeing contacted by said rolls at a suflicient frequency and energy levelso as to reduce the grain size of the metal in said metal member as thethickness of said metal member is being reduced by being passed betweensaid rolls.

11. A method in accordance with claim 10 in which the rolls are vibrated180 degrees out of phase in respect to each other.

12. A method of rolling .a metal comprising passing, a

metal member between a pair of rotating rolls, reducing the thickness ofthe metal member by applying sufiicient force through said rolls whilesaid rolls are engaged with the metal member, and simultaneouslyintroducing vibratory energy in a direction substantially perpendicularto the applied force through at least one of said rolls to the surfaceor the metal member, said vibratory energy being of a sufficientfrequency and energy level so as to reduce the grain size of the metalin said metal member as the thickness of said metal is being reduced bypassage between said rolls.

13. A method of rolling a metal sheet comprising moving a metal sheetbetween a pair of rotating rolls, reducing the thickness of said movingmetal sheet by engaging the surfaces of said moving metal sheet withsaid rolls under conditions of suflicient force, and simultaneouslyapplying vibratory energy to the surface of the metal sheet engaging oneof said rolls, said vibratory energy being applied in a directionparallel to the plane of the metal sheet disposed between said rolls,said vibratory energy being at a sufficient frequency and energy levelso as to reduce the grain size of the metal in said metal sheet as thethickness of said metal sheet is being reduced by its movement betweensaid rolls.

14. A method of rolling a metal sheet in accordance with claim 13wherein the applied vibratory energy is within the frequency range of 20cycles per second to 250,000 cycles per second.

15. A method of rolling a metal comprising passing a metal memberbetween .a pair of rotating rolls, reducing the thickness of the memberby applying sufiicient force through said rolls while said rolls areengaged with the member, and reducing the amount of said force necessaryto achieve a predetermined amount of reduction in the thickness of saidmember by introducing vibratory energy to at least one of said rolls ina direction substantially perpendicular to the direction of applicationof said force.

16. A method in accordance with claim 15 wherein said vibratory energyis continuous ultrasonic vibratory energy.

17. A method in accordance with claim 15 wherein said vibratory energyis introduced in a direction parallel to the surface of the metal memberbeing contacted by said rolls.

References Cited in the file of this patent UNITED STATES PATENTS2,995,050 Karron et a1 Aug. 8, 1961

9. A METHOD OF ROLLING A METAL COMPRISING PASSING A METAL MEMBER BETWEENA PAIR OF ROTATING ROLLS, REDUCING THE THICKNESS OF THE METAL MEMBER BYAPPLYING SUFFICIENT FORCE THROUGH SAID ROLLS WHILE SAID ROLLS AREENGAGED WITH SAID METAL MEMBER, AND SIMULTANEOUSLY VIBRATING AT LEASTONE OF SAID ROLLS IN A DIRECTION PARALLEL TO THE SURFACE OF THE METALMEMBER BEING CONTACTED AS THE THICKNESS OF SAID METAL MEMBER IS BEINGREDUCED BY BEING PASSED BETWEEN SAID ROLLS.